Comment # 8 on bug 899405 from Johannes Meixner

Regarding comment#6:

As soon as the HPLIP software with its problematic filtering rules
is installed, those filtering rules apply for all print jobs.

See https://bugzilla.suse.com/show_bug.cgi?id=735404#c52
"HPLIP adds CUPS filtering rules ... those rules become part
 of the standard CUPS filtering which means those rules
 affect all print jobs".

This means HPLIP's filtering rules are also used for print jobs
for printer devices from other manufacturers.